Northern Soldiers Became Increasingly Convinced of Slavery's Evils When

Northern soldiers became increasingly convinced of slavery's evils when

A) Congress passed the Thirteenth Amendment to the Constitution.
B) abolitionists praised Lincoln's Emancipation Proclamation.
C) slaves ran away to Union camps and persevered against all odds.
D) Confederate politicians stopped defending the legitimacy of slavery.
E) All of these choices are correct.